Having a multi-signature wallet

Say you have a partnership and you don't want either partner to have sole ability to withdraw from a wallet. You could have a 2 out of 3 signature but if it's you and two other people, those two could theoretically conspire against you and steal the crypto. So, back to a 2-signature wallet. Is there a concern for... what happens if one partner becomes incapacitated? If s/he dies, I guess you could send a death certificate and probate documents and somebody else could do the signature for the deceased? But what about incapacitation? Just say one becomes disabled or very ill and unable to really function? Has anyone solved this?